Analysis of Indirect Measurement of Cutting Forces Turning Metal Cylindrical Shells

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. Abstract Cutting forces measurement is an important component of the machining processes development and control. The use of conventional direct measurement systems is often impossible as they interfere in the process's dynamics. This work proposes a method of cutting force indirect estimation during turning thin-walled cylindrical shells. Calculation of the flexibility matrix has enabled us to relate measured displacements of certain workpiece's points to the cutting force. An optimization approach for choosing the measurement points location has been proposed, based on the best conditioning of the flexibility matrix.

Multi-cutter turning process stability analysis

“…At certain conditions, the turning process involving constant chip thickness incurs dynamic instability [5][6][7][8]11]. The loss of stability and the onset of auto-oscillations may be sensitive to several phenomena, such as the regenerative cutting of the surface created by the previous tool pass, ploughing caused by the flank face interaction, workpiece flexibility, temperature-induced effects [8][9][10][11][12][13][14]. In the case of multi-cutter turning, the deflection (vibrations) of the cutters is an important parameter.…”

Nonlinear Regenerative Dynamics Analysis of the Multicutter Turning Process

“…Thus, the amount of matter removed during this surface generation is comprised between the actual jth cutter position at current time t and the position of the previous cutter at time t − t j−1 , where t j−1 = ϕ j−1 /ω is the delay between cutters (j and (j-1)). These features can be described by the following relationships, based on [7,8,9,15]:…”

“…Under certain conditions, the cutting with constant depth can become dynamically unstable. The problems of oscillations arising during machining has been discussed in numerous works [6,15,17,18,21]. One of the reasons for the loss of stability are nonlinear phenomena underlying the cutting and friction forces (in particular, ploughing on the flank face of the cutter), depending on the relative motion in the cutting interaction zone, and potentially leading to the interrupted cut (chip fragmentation) [5,16,17].…”

“…Another class of important causes of instabilities are the regeneration of cut surfaces (i.e., cutting the surfaces formed during the previous pass of the cutter), workpiece flexibility, temperature effects etc. [1,3,6,15]. One of the important problems in the technological processes of turning is the self-excitation of the cutting tool vibration.…”